Embodiments generally relate to a charge storage assembly, and, more particularly, to a system and method for forming a charge storage assembly that may be used with a medical device.
Numerous medical devices exist today, including but not limited to electrocardiographs (“ECGs”), electroencephalographs (“EEGs”), squid magnetometers, implantable pacemakers, implantable cardioverter-defibrillators (“ICDs”), neurostimulators, electrophysiology (“EP”) mapping and radio frequency (“RF”) ablation systems, and the like (hereafter generally “implantable medical devices” or “IMDs”). IMDs commonly employ one or more leads with electrodes that either receive or deliver voltage, current or other electromagnetic pulses (generally “energy”) from or to an organ or tissue (collectively hereafter “tissue”) for diagnostic or therapeutic purposes.
Certain types of IMDs include internal charge storage members, such as one or more capacitors. The charge storage members may be connected to a switch circuit or network also referred to as an H-bridge. Conventional high voltage H-bridges include a network of transistors that are controlled to open and close in different combinations to deliver stored energy from the charge storage members to a patient through the electrodes.
Typically, a capacitor of an IMD includes a stack assembly having anodes and cathodes secured within a housing. The housing may include a case and a lid. After the stack assembly is secured within the case, the lid is positioned over the case. The lid and the case are then secured together, such as through welding at seams between the lid and the case.
Typically, the outer, exposed edges of the case are inwardly-offset toward an interior chamber of the case. The offset forms a recessed area about the outer edges that receives an outer edge of the lid. The lid and the case are then typically laser-welded proximate an interface between the lid and the case.
However, the inward offset of the case occupies space within the case. Accordingly, the case typically needs to be large enough to accommodate the stack assembly. Yet, with IMDs becoming smaller, internal space within the IMDs may be at a premium. The inward offset of the case into the internal chamber of the case may cause the capacitor to be too large for some applications.